When a clamping stud having a clamping head which is engageable in the aperture of an apertured cutting element is used to secure the cutting element to a shank having a support surface for the cutting element in which is provided a hole to receive the shaft of the clamping stud, it is important that the clamping stud be securely locked in the shank so that it cannot be gradually loosened by forces acting in various directions which are produced by chattering of the cutting element during a cutting operation.
The shaft of a clamping stud can be locked securely in the hole provided in the shank of a tool holder by the use of a locking screw having teeth which engage with teeth provided on the shaft of the clamping stud, if the force exerted by the teeth on the locking screw acts in a direction which is non-parallel to the axis of the shaft, so as to produce a wedging driving action upon the shaft.
It has now been found that such a locking screw, although it locks the clamping stud securely in place so that the clamping stud does not become loosened by chattering of the cutting element, is subject to a new difficulty in that such a locking screw, when tightened sufficiently to secure the clamping stud firmly in place, is liable to jam the mechanism so that it is difficult or impossible to remove the locking screw.